1. Technical Field
The present invention relates to a head-mounted display device and a control method for the head-mounted display device.
2. Related Art
There is known a head-mounted display device (a head mounted display (HMD)), which is a display device worn on the head. For example, the head-mounted display device generates image light, which represents an image, using a liquid crystal display and a light source and guides the generated image light to the eyes of a user using a projection optical system and a light guide plate to thereby cause the user to recognize a virtual image.
In recent years, the HMD has been advanced in high functionality. An HMD having a function equivalent to the function of a personal computer has emerged on the market. In the high-function HMD, personal information and the like are often stored in the HMD. Therefore, improvement of security is demanded in the HMD as in the personal computer. There is known a technique for recognizing whether a user of an HMD is a proper user in order to achieve improvement of security in the HMD. In the following explanation, authenticating whether a user is a proper user is simply referred to as “authenticate” as well. For example, JP-A-6-314259 (Patent Literature 1) describes an HMD that photographs an image of an eye of a user and determines whether the photographed image matches an image registered in advance to thereby perform authentication of the user.
In the technique described in Patent Literature 1, an outsider can impersonate a proper user by acquiring in advance a photograph of an eye of the proper user, for example, a commemorative photograph or an identification photograph.
Therefore, there is a demand for a technique capable of reducing a risk of the impersonation and realizing authentication with further improved security in a head-mounted display device (HMD).